[6/7,v2] tracing: Add some more locked_down checks

Message ID	20191012005921.411873502@goodmis.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=bMKJ=YF=vger.kernel.org=linux-security-module-owner@kernel.org> Message-Id: <20191012005921.411873502@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 11 Oct 2019 20:57:53 -0400 From: Steven Rostedt <rostedt@goodmis.org> To: linux-kernel@vger.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org>, Ingo Molnar <mingo@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Matthew Garrett <matthewgarrett@google.com>, James Morris James Morris <jmorris@namei.org>, LSM List <linux-security-module@vger.kernel.org>, Linux API <linux-api@vger.kernel.org>, Ben Hutchings <ben@decadent.org.uk>, Al Viro <viro@zeniv.linux.org.uk> Subject: [PATCH 6/7 v2] tracing: Add some more locked_down checks References: <20191012005747.210722465@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	tracing: Fix tracefs lockdown and various clean ups \| expand [0/7,v2] tracing: Fix tracefs lockdown and various clean ups [1/7,v2] tracefs: Revert ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is locked down") [2/7,v2] ftrace: Get a reference counter for the trace_array on filter files [3/7,v2] tracing: Get trace_array reference for available_tracers files [4/7,v2] tracing: Have trace events system open call tracing_open_generic_tr() [5/7,v2] tracing: Add tracing_check_open_get_tr() [6/7,v2] tracing: Add some more locked_down checks [7/7,v2] tracing: Do not create tracefs files if tracefs lockdown is in effect

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8b765a55e01c..f296d89be757 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -18,6 +18,7 @@ #include <linux/clocksource.h> #include <linux/sched/task.h> #include <linux/kallsyms.h> +#include <linux/security.h> #include <linux/seq_file.h> #include <linux/tracefs.h> #include <linux/hardirq.h> @@ -3486,6 +3487,11 @@ static int ftrace_avail_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; if (unlikely(ftrace_disabled)) return -ENODEV; @@ -3505,6 +3511,15 @@ ftrace_enabled_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; + /* + * This shows us what functions are currently being + * traced and by what. Not sure if we want lockdown + * to hide such critical information for an admin. + * Although, perhaps it can show information we don't + * want people to see, but if something is tracing + * something, we probably want to know about it. + */ + iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); if (!iter) return -ENOMEM; @@ -3625,6 +3640,7 @@ ftrace_filter_open(struct inode *inode, struct file *file) { struct ftrace_ops *ops = inode->i_private; + /* Checks for tracefs lockdown */ return ftrace_regex_open(ops, FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, inode, file); @@ -3635,6 +3651,7 @@ ftrace_notrace_open(struct inode *inode, struct file *file) { struct ftrace_ops *ops = inode->i_private; + /* Checks for tracefs lockdown */ return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, inode, file); } @@ -5203,9 +5220,13 @@ static int __ftrace_graph_open(struct inode *inode, struct file *file, struct ftrace_graph_data *fgd) { - int ret = 0; + int ret; struct ftrace_hash *new_hash = NULL; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + if (file->f_mode & FMODE_WRITE) { const int size_bits = FTRACE_HASH_DEFAULT_BITS; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 26ee280f852b..2b4eff383505 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -17,6 +17,7 @@ #include <linux/stacktrace.h> #include <linux/writeback.h> #include <linux/kallsyms.h> +#include <linux/security.h> #include <linux/seq_file.h> #include <linux/notifier.h> #include <linux/irqflags.h> @@ -306,6 +307,12 @@ void trace_array_put(struct trace_array *this_tr) int tracing_check_open_get_tr(struct trace_array *tr) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + if (tracing_disabled) return -ENODEV; @@ -6813,6 +6820,7 @@ static int snapshot_raw_open(struct inode *inode, struct file *filp) struct ftrace_buffer_info *info; int ret; + /* The following checks for tracefs lockdown */ ret = tracing_buffers_open(inode, filp); if (ret < 0) return ret; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ae35d6cb802a..994b7a408c5f 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -12,6 +12,7 @@ #define pr_fmt(fmt) fmt #include <linux/workqueue.h> +#include <linux/security.h> #include <linux/spinlock.h> #include <linux/kthread.h> #include <linux/tracefs.h> @@ -1294,6 +1295,8 @@ static int trace_format_open(struct inode *inode, struct file *file) struct seq_file *m; int ret; + /* Do we want to hide event format files on tracefs lockdown? */ + ret = seq_open(file, &trace_format_seq_ops); if (ret < 0) return ret; @@ -1750,6 +1753,10 @@ ftrace_event_open(struct inode *inode, struct file *file, struct seq_file *m; int ret; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + ret = seq_open(file, seq_ops); if (ret < 0) return ret; @@ -1774,6 +1781,7 @@ ftrace_event_avail_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_event_seq_ops; + /* Checks for tracefs lockdown */ return ftrace_event_open(inode, file, seq_ops); } diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index dd18d76bf1bd..57648c5aa679 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -7,6 +7,7 @@ #include <linux/module.h> #include <linux/kallsyms.h> +#include <linux/security.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/stacktrace.h> @@ -1448,6 +1449,10 @@ static int synth_events_open(struct inode *inode, struct file *file) { int ret; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { ret = dyn_events_release_all(&synth_event_ops); if (ret < 0) @@ -5515,6 +5520,12 @@ static int hist_show(struct seq_file *m, void *v) static int event_hist_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return single_open(file, hist_show, file); } diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 2a2912cb4533..2cd53ca21b51 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -5,6 +5,7 @@ * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com> */ +#include <linux/security.h> #include <linux/module.h> #include <linux/ctype.h> #include <linux/mutex.h> @@ -173,7 +174,11 @@ static const struct seq_operations event_triggers_seq_ops = { static int event_trigger_regex_open(struct inode *inode, struct file *file) { - int ret = 0; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; mutex_lock(&event_mutex); @@ -292,6 +297,7 @@ event_trigger_write(struct file *filp, const char __user *ubuf, static int event_trigger_open(struct inode *inode, struct file *filp) { + /* Checks for tracefs lockdown */ return event_trigger_regex_open(inode, filp); } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 324ffbea3556..1552a95c743b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -7,11 +7,11 @@ */ #define pr_fmt(fmt) "trace_kprobe: " fmt +#include <linux/security.h> #include <linux/module.h> #include <linux/uaccess.h> #include <linux/rculist.h> #include <linux/error-injection.h> -#include <linux/security.h> #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ @@ -936,6 +936,10 @@ static int probes_open(struct inode *inode, struct file *file) { int ret; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { ret = dyn_events_release_all(&trace_kprobe_ops); if (ret < 0) @@ -988,6 +992,12 @@ static const struct seq_operations profile_seq_op = { static int profile_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return seq_open(file, &profile_seq_op); } diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index c3fd849d4a8f..d4e31e969206 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -6,6 +6,7 @@ * */ #include <linux/seq_file.h> +#include <linux/security.h> #include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/ftrace.h> @@ -348,6 +349,12 @@ static const struct seq_operations show_format_seq_ops = { static int ftrace_formats_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return seq_open(file, &show_format_seq_ops); } diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index ec9a34a97129..4df9a209f7ca 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -5,6 +5,7 @@ */ #include <linux/sched/task_stack.h> #include <linux/stacktrace.h> +#include <linux/security.h> #include <linux/kallsyms.h> #include <linux/seq_file.h> #include <linux/spinlock.h> @@ -470,6 +471,12 @@ static const struct seq_operations stack_trace_seq_ops = { static int stack_trace_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return seq_open(file, &stack_trace_seq_ops); } @@ -487,6 +494,7 @@ stack_trace_filter_open(struct inode *inode, struct file *file) { struct ftrace_ops *ops = inode->i_private; + /* Checks for tracefs lockdown */ return ftrace_regex_open(ops, FTRACE_ITER_FILTER, inode, file); } diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 75bf1bcb4a8a..9ab0a1a7ad5e 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -9,7 +9,7 @@ * */ - +#include <linux/security.h> #include <linux/list.h> #include <linux/slab.h> #include <linux/rbtree.h> @@ -238,6 +238,10 @@ static int tracing_stat_open(struct inode *inode, struct file *file) struct seq_file *m; struct stat_session *session = inode->i_private; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + ret = stat_seq_init(session); if (ret) return ret; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index dd884341f5c5..352073d36585 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -7,6 +7,7 @@ */ #define pr_fmt(fmt) "trace_uprobe: " fmt +#include <linux/security.h> #include <linux/ctype.h> #include <linux/module.h> #include <linux/uaccess.h> @@ -769,6 +770,10 @@ static int probes_open(struct inode *inode, struct file *file) { int ret; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { ret = dyn_events_release_all(&trace_uprobe_ops); if (ret) @@ -818,6 +823,12 @@ static const struct seq_operations profile_seq_op = { static int profile_open(struct inode *inode, struct file *file) { + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + return seq_open(file, &profile_seq_op); }

[6/7,v2] tracing: Add some more locked_down checks

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